Fix validation messages

[justin-tay]

This makes the following changes

• Makes the english messages more consistent. Some of the messages use different phrasing for the same meaning.
• The messages for unevaluatedProperties and unevaluatedItems when using a schema that is not false now just let those messages be returned instead of modifying the message. This is consistent with the other validators handling of this eg. additionalProperties.
• The oneOf now returns the matching indexes. Note that in a typical short circuit case this will only return 2 instead of potentially more.

An attempt was made to fix the translations of jsv-messages.properties. Most of them are all corrupt and have ? or � characters. Others are encoded in UTF-8 which is not supported in Java 8. UTF-8 in resource bundles are only supported from Java 9. In Java 8 they must be encoded in ISO-8859-1 with unsupported characters escaped. A LocaleTest was added to ensure that the translated messages are working as expected. A native speaker would be required for a proper fix.

[codecov-commenter]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (7cda40e) 78.65% compared to head (8699200) 78.59%.

Files	Patch %	Lines
...n/java/com/networknt/schema/MaxItemsValidator.java	50.00%	1 Missing :warning:
...om/networknt/schema/UnevaluatedItemsValidator.java	83.33%	0 Missing and 1 partial :warning:

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #969 +/- ## ============================================ - Coverage 78.65% 78.59% -0.06% Complexity 1810 1810 ============================================ Files 161 161 Lines 5893 5887 -6 Branches 1116 1119 +3 ============================================ - Hits 4635 4627 -8 Misses 833 833 - Partials 425 427 +2 ```

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